eng_u250.dll is a ENG_U232.DLL
belonging to L&H American English TTS SDK
from Lernout & Hauspie Speech Products
Non-system processes like eng_u250.dll originate from software you installed on your system. Since most applications store data in your system's registry, it is likely that your registry has suffered fragmentation and accumulated invalid entries which can affect your PC's performance. It is recommended that you check your registry to identify slowdown issues.